China’s largest rare earths producer, Baotou, has suspended production for one month in an effort to prop up falling prices, in the clearest signal yet that Chinese producers are intent on supporting prices at high levels.

China is the world’s biggest producer of rare earths, but tightening government controls and stockpiling has sent rare earths prices rocketing this year, with prices for some minerals increasing more than eight times during the first half of the year.

Rare earths prices have been sliding since their peak in July, but the slide has accelerated during the past week. Neodymium, which is used in magnets, has fallen 9 per cent, while Lanthanum, which is used in fuel catalytic converters, has fallen 12 per cent, according to prices from Shanghai Metals Market.